Inactivation of metal deactivators in gasoline

ABSTRACT

7. A method of preparing a flame thrower fuel from a gasoline containing from one to three pounds per 1000 bbls. of a metal deactivator selected from the group consisting of N,N1 disalicylidene 1, 2 diamino propane and N,N1 disalicylidene 1, 2 diaminoethylene which comprises percolating said gasoline through a bed of nuclear sulfonated cross linked styrene-divinyl benzene copolymer and thereafter gelling said gasoline with about 2 percent of an aluminum soap selected from the class consisting of aluminum hydroxy di-2 ethyl hexoate and the aluminum hydroxy disoap of mixed branched chained octoic acids.

United States Patent Frederick N. Baumgartner Plainfield, NJ.

Jan. 23, 1969 Dec. 21, 1971 The United States of America as represented by the Secretary of the Army [72] Inventor [21 App]. No. [22] Filed [45] Patented [73] Assignee [54] INACTIVATION OF METAL DEACTIVATORS IN GASOLINE 7 Claims, No Drawings [52] U.S. Cl. 44/7 A, 44/7 R, 149/109, 208/17 [51] lnt.Cl C1017/02 [50] Field of Search 44/7, 7.2,

[56] References Cited UNITED STATES PATENTS 2,751,360 6/1956 Van Strien 44/7 2,774,740 12/1956 Magram 44/7 2,870,095 1/1959 Ratzer et al 44/7 Primary Examiner- Benjamin R. Padgett Attorneys-George Renehan and Edward J. Kelly ENACTIVATION F METAL DEACTIVATORS lN GASOLINE This invention relates to the treatment of gasoline containing metal deactivators to make it suitable for gelling by aluminum soaps to produce a flame-thrower fuel or a filling for firebombs.

Metal deactivators are quite frequently used as additives in gasoline. Their purpose is to remove harmful metallic ions from the gasoline by forming innocuous chelate compounds. These deactivators are most generally of the Schiff base type: RN CHR'. in this formula R and R are organic radicals including hydroxy aromatic groups, or hydroxy-substituted heterocyclic nitrogen containing radicals having the aromatic" linkage, e.g. hydroxy pyridyl, with the OH ortho to the N or CH=N group attached to the aromatic ring.

Numerous deactivators of this class are disclosed in the prior art. Thus, U.S. Pat. No. 2,249,602 discloses compounds having that structural formula in which R and R are hydroxy cresyl groups. U. S. Pat. No. 2,282,936 discloses compounds in which R is a hydroxy naphthyl or substituted hydroxy naphthyl group and R is hydroxy phenyl or hydroxy cresyl. ln U.S. Pat. No. 2,181,121, 2,181,122, 2,255,597 and 2,284,267 an extensive group of deactivators is disclosed having the formula OH--A--CHENRN.,=.CHAOH where A is an aromatic or an unsaturated hetero-nitrogen ring group and R is an aliphatic hydrocarbon group. Each 01-! is ortho to a CH'= N group. US. Pat. No. 2,813,089 discloses concentrated liquid solutions of this group of compounds which are said to be more convenient for addition to gasoline than the compounds alone. In my specifications and claims, 1 designate this class by the term Schiffs-base-type metal deactivators."

A common, although by no means the only, metal deactivator in current use is the compound N, N -disalicylidene-l, 2- diaminopropane specifically disclosed in U.S. Pat. No. 2,284,267. This particular additive is used by the military and is presently added to all automotive combat gasoline. [t is present to the extent of not less than 1 1b. and no more than 3 lbs. per 1000 barrels of gasoline or about 4-12 p.p.m. The military specifications also pennit the use, in the same quantities, of the closely related compound N, N disalicylidene-l 2- diaminoetlrylene. Although the deactivator undoubtedly is of value when dissolved metal (such as may have come from a copper sweetening process) is present in the gasoline and the gasoline is being used as fuel for internal combustion engines, the deactivator is very harmful for certain other gasoline uses. One such use is the preparation of gelled-gasoline flame thrower fuel. The action of the metal activator is to form a chelate compound with the aluminum which is introduced in the form of aluminum disoap" to form the gel. The deactivator thus removes the aluminum from the soap, causing a breakdown in the soap polymer structure and resulting in a weakened gel. Fuels prepared from aluminum soap thickeners and automotive combat gasoline are notoriously unstable, often completely deteriorating in less than 48 hours. Gasoline which does not contain metal deactivator gives very stable gels lasting weeks instead of hours.

it is the purpose of this invention, therefore, to remove or to render inactive the metal deactivator present in an amount of 4-12 p.p.m. in a hydrocarbon fuel such as gasoline.

it is well known that Schiff bases are unstable in the presence of aqueous acid. It therefore follows that decomposition or these compounds in a gasoline can be accomplished by contacting the gasoline with aqueous acid. This procedure, however, suffers in that for the purposes heretofore described such an operation is almost completely unfeasible. Such a liquid-liquid contacting procedure could be carried out only with extensive equipment. ln addition, the gasoline would have to be very carefully dried since small amounts of water andlor acid are very harmful to the preparation of thickened fuels.

1 have found that the metal deactivator may be rendered inactive toward aluminum soap thickeners by contacting the gasoline with a cation exchange resin of the sulfonic acid type in its acid or hydrogen form. One type that l have found to be suitable is the sulfonated styrene-divinyl benzene copolymer type described in U.S. Pat. No, 2,366,077 granted Dec. 26, 1944 to Vincent D'Alellio and U.S. Pat. No. 2,466,675 granted Apr. 12, 1948 to William C. Bauman, (example 5). Another type consists of the sulfonated proliferous copolymers of styrene with other vinyl hydrocarbons described in U.S. Pat. No. 2,597,438 granted May 20, 1952 to George W. Bodamer. These cation exchangers are all nuclearsulfonated cross-linked polymers of styrene. A specific product that we have used successfully is that sold commercially under the name Dowex 50-X8. This is a nuclear sulfonated granular copolymer of 92 percent styrene with 8 percent divinyl benzene cross linking. It has a total exchange capacity of 4.5 miliequivalents per gram, or approximately 50 kilograins of calcium carbonate per cubic foot. Another is Dowex 50-X4 which is the same as just described, except that it has 4 percent divinyl benezene cross-linking.

Another type cation exchange resin that may be successfully employed is the wellknown sulfonated phenol-formaldehyde type disclosed in many patents, e.g. U.S. Pat. No. 2,466,675 (cited above) (examples l-4) and U.S. Pat. No. 2,448,029, granted Aug. 26, 1948 to George Beal Heusted and William C. Bauman.

Cation exchange resins of the type employed by me are disclosed in detail, and further examples are given, in lon Exchangers in Analytical Chemistry" by Olof Samuelson, copyright 1953 by John Wiley and Sons, pages 12-27, 262 and 263.

The following specific examples illustrate this invention.

EXAMPLE 1 A synthetic hydrocarbon test solvent as prescribed by the U.S. Military Standard Mll-STD-602 was used instead of gasoline. DuPont liquid metal deactivator (N, N -disalicylidene-1,2-diamino propane) was added in the proportion of 3 lb. deactivator per 1000 bbls. of test solvent. The test solvent, alone and with deactivator, was gelled by 2 percent aluminum hydroxy di 2-ethylhexoate, designated by the U.S. Army as Thickener M3 in the presence of 1 percent 2-ethylhexoic acid as a peptizer. The gel was held 24 hours at F. and the consistency determined with the Gardner Mobilometer. The consistency determination is a type of viscosity measurement and is described fully in JAN-l-7l l, 16 Dec. 1948, National Military Establishment Specification, lncendiary Oils, Consistency of, Test Procedures, Section: Mobilometer Methods. This is a standard test for the stability of the gel produced by the aluminum soap. The heating of the gel is in effect an accelerated aging test. The higher the Gardner consistency, the more stable the gel. Results obtained were as follows.

it will be noted that the detrimental effect of the deactivator is completely removed by the treatment with the ion exchanger.

EXAMPLE 11 This series of tests shows results obtained with actual military gasoline and affords a basis for comparison between this gasoline and the test solvent utilized in example 1. It also compares results obtained with the two ion exchangers, Dowex 50X8 and Dowex 50-X4, described above. The test solvent and gasoline were gelled by the addition of 2 percent aluminum hydroxy di 2 -ethyl hexoate with 1 percent Z-ethyl hexoic acid added as a peptizer and heated for 24 at 150 C. The Gardner consistency was then determined. The results were as follows.

TABLE II Average Gardner Hydrocarbon Consistency (a) Test Solvent (b) Gasoline as received (c) Gasoline percolated through Dower 50-X8 (d) Gasoline percolated through Dowex SO-X 4 (e) Gasoline as received (recheck after 8 days) The gasoline was Referee Grade, obtained from Aberdeen Proving Ground, Maryland, and conformed to Military Specification Mil-G-Mlfiti A, containing 1.0 lb. per 1000 bbl. of DuPont Metal Deactivator (N, N-disalicylidene- 1,2 diaminopropane).

EXAMPLE Hi This series of tests involved use of the same tests solvent, gasoline and activator as in example 2, but a different aluminum soap thickener, that designated by the US. Army Chemical Corps as thickener E4Rl .This is the aluminum soap of mixed branched chain octoic acids described in U.S. Pat. No. 2,718,462 and 2,746,629, granted to Leonard Cohen. Tests were run on the various hydrocarbons gelled with 2 percent and 4 percent of the ErRl thickener. (Since these tests were run this thickener has been standardized by the Army and is now designated M4). Tests were run utilizing 4 percent thickener, typical of firebomb fillings, as well as 2 percent, typical of flame-thrower fuels. No free acid was employed as a peptizer, and the gel was stored at 75 F. The Gardner consistency was determined after 1 day and after 4 weeks. Results are shown in table 3.

TABLE 3 Gardner consistency of gel H ydrocarbon (a) Test solvent (b) Test solvent plus deactivator (3 lb./1.000 bbls.) A (c) (bl percolated through Dowex (d) Gasollinc (l lb. deactivator/1,000

bb s. c r V c V ,7 (c) Gasoline pcrcolated through Dowex fill-X8 claims.

lclaim: 1. The process which comprises contacting a liquid hydrocarbon containing a Schiff's-base-t pe metal deactiyatpr with a cation exchange team of the sul onlc acld type in its hydrogen fonn.

2. A process as defined in claim I wherein said cation exchange resin is a nuclear-sulfonated cross linked polymer of styrene.

3. A process as defined in claim 2 wherein said metal deactivator is selected from the group consisting of N, N'-disalicylidene-, l, Zand N, N -disalicylidene, l Z-diaminoethylene.

4. A method of preparing a military incendiary fuel from a liquid hydrocarbon containing a Schiff's-base-type metal deactivator, which comprises contacting said hydrocarbon with a cation exchange resin of the sulfonic acid type in its hydrogen form and then gelling said hydrocarbon an aluminum soap thickener.

5. A method as defined in claim 4 wherein said ion exchange resin is a nuclear-sulfonated cross linked polymer of styrene.

6. A method as defined in claim 5 wherein said deactivator is selected from the glass consisting of N, Ndisalicylidene-l, Z-diaminopropane and N, N -disalicylidenel, 2- diaminoethylene.

7. A method of preparing a flame thrower fuel from a gasoline containing from i to 3 pounds per 1000 bbls. of a metal deactivator selected from the group consisting of N, Ndisalicylidene l, Z-diaminopropane and N, N'disalicylidene l, Z-diaminoethylene which comprises percolating said gasoline through a bed of nuclear sulfonated cross linked styrene-divinyl benzene copolymer and thereafter gelling said gasoline with about 2 percent of an aluminum soap selected from the class consisting of aluminum hydroxy di-2-ethyl hexoate and the aluminum hydroxy disoap of mixed branched chained octoic acids.

t a a a a 

1. The process which comprises contacting a liquid hydrocarbon containing a Schiff''s-base-type metal deactivator with a cation exchange resin of the sulfonic acid type in its hydrogen form.
 2. A process as defined in claim 1 wherein said cation exchange resin is a nuclear-sulfonated cross linked polymer of styrene.
 3. A process as defined in claim 2 wherein said metal deactivator is selected from the group consisting of N, N1-disalicylidene--, 1, 2and N, N1-disalicylidene,1, 2-diaminoethylene.
 4. A method of preparing a military incendiary fuel from a liquid hydrocarbon containing a Schiff''s-base-type metal deactivator, which comprises contacting said hydrocarbon with a cation exchange resin of the sulfonic acid type in its hydrogen form and then gelling said hydrocarbon an aluminum soap thickener.
 5. A method as defined in claim 4 wherein said ion exchange resin is a nuclear-sulfonated cross linked polymer of styrene.
 6. A method as defined in claim 5 wherein said deactivator is selected from the glass consisting of N, N1-disalicylidene-1, 2-diaminopropane and N, N1-disalicylidene1, 2-diaminoethylene.
 7. A METHOD OF PREPARING A FLAME THROWER FUEL FROM A GASOLINE CONTAINING FROM ONE TO THREE POUNDS PER 1000 BBLS. OF A METAL DEACTIVATOR SELECTED FROM THE GROUP CONSISTING OF N,N1 DISALICYLIDENE 1, 2 DIAMINO PROPANE AND N,N1 DISALICYLIDENE 1, 2 DIAMINOETHYLENE WHICH COMPRISES PERCOLATING SAID GASOLINE THROUGH A BED OF NUCLEAR SULFONATED CROSS LINKED STYRENE-DIVINYL BENZENE COPOLYMER AND THEREAFTER GELLING SAID GASOLINE WITH ABOUT 2 PERCENT OF AN ALUMINUM SOAP SELECTED FROM THE CLASS CONSISTING OF ALUMINUM HYDROXY DI-2 ETHYL HEXOATE AND THE ALUMINUM HYDROXY DISOAP OF MIXED BRANCHED CHAINED OCTOIC ACIDS. 